Page 1 PROBLEM 3.1 KNOWN: One-dimensional, plane wall ...

PROBLEM 3.21KNOWN: Thickness, overall temperature difference, and pressure for two stainless steelplates.FIND: (a) Heat flux and (b) Contact plane temperature drop.SCHEMATIC:ASSUMPTIONS: (1) One-dimensional heat transfer, (2) Steady-state conditions, (3)Constant properties.PROPERTIES: Table A-1, Stainless Steel (T ≈ 400K): k = 16.6 W/m⋅K.ANALYSIS: (a) WithR′′ 4 2t,c ≈ 15× 10−m ⋅ K/W from Table 3.1 andL 0.01m= = 6.02× 10−4 m2⋅K/W,k 16.6 W/m ⋅Kit follows thathence4 2( ) −R′′ tot = 2 L/k + R′′t,c ≈ 27× 10 m ⋅K/W;$∆T100 Cq ′′ = = = 3.70×104W/m2.R′′ tot 27× 10-4m2⋅K/W(b) From the thermal circuit,Hence,∆ T4 2cR′′t,c 15× 10−m ⋅K/W = = = 0.556.T -4 2s,1 − Ts,2 R′′tot 27× 10 m ⋅K/W( ) ( )∆ Tc = 0.556 Ts,1 − Ts,2= 0.556 100 C = 55.6 C.$ $